1. Field of the Invention
This invention relates to a method for collecting a small blood sample by painlessly puncturing fingers of a hand.
2. Prior Art
Self monitoring of blood glucose (SMBG) for diabetic patients has been performed using blood obtained by needle puncture of the finger tips (palm side, lateral side), which contain many pain spots. The depth of puncture achieved by puncture devices used for SMBG is preferably in the range of 0.5 mm to 2.0 mm. Moreover, the range of 0.7 mm to 1.3 mm has been considered to be particularly important (refer to U.S. Pat. No. 5,318,584). Moreover, the error in the depth of puncture has been known to be more than ±0.3 mm (refer to U.S. Pat. No. 5,318,584). According to the conventional technique, pain accompanied with puncture of finger tips can not be avoided, because the puncture is performed at a site having many pain spots, and because the depth of the puncture is deep. Recently, attempts to avoid pain accompanied with blood collection have been made by performing punctures at abdominal areas or on the forearm, which have comparatively fewer pain spots. However, complete elimination of pain can not be realized by using this method. Moreover, delayed alteration in blood glucose level measured by puncture of forearm compared with fingertip has been reported. Therefore, there has been a demand for the development of a painless method for collecting blood from the fingers.